The purpose of this project is to 1) develop improved membranes, membrane lungs, and membrane lung systems for prolonged pulmonary and cardiopulmonary support. Major efforts have centered on developing improved carbon dioxide membrane lungs for enhanced removal of carbon dioxide from extracorporeal blood; 2) to develop methods for the extracorporeal removal of carbon dioxide for the control of breathing; 3) to develop an animal model system using the pre-term lamb to study the use of the carbon dioxide membrane lung on the development of hyaline membrane disease (HMD).